Direction controlled service apparatus

ABSTRACT

A direction controlled service apparatus may include a mounting assembly, a housing assembly configured to operably connect to the mounting assembly, the housing assembly being movable with respect to the mounting assembly, and a plurality of actuators connected between the mounting assembly and the housing assembly, each actuator of the plurality of actuators being configured to contract upon a current being applied to the actuator to rotate the housing assembly with respect to the mounting assembly.

PRIORITY

This application is a divisional of U.S. Ser. No. 15/257,177 filed onSep. 6, 2016, which is a divisional of U.S. Ser. No. 13/863,360 filed onApr. 15, 2013 (now U.S. Pat. No. 9,457,907).

FIELD

The present disclosure is generally related to aircraft passengerservice units and, more particularly, to a direction controlled serviceapparatus for use with a passenger service panel of an aircraft.

BACKGROUND

Passenger service units are found in commercial or passenger aircraftabove the rows of seats and are used to provide various servicefunctions to the passengers. Typically these service functions includereading lights, personal air outlets, commonly referred to as gaspers,illuminated display symbols, and a flight attendant call. The controlsfor these service functions are generally disposed on a service panel ofthe passenger service unit above the seats.

One major disadvantage of the service function control is location. Forexample, it may be difficult for a shorter passenger, a child, or apassenger with limited mobility to reach the controls of the servicepanel. Thus, the passenger may not have the ability to turn on thereading light, adjust the air flow of the personal air outlet, or adjustthe direction or position of either the reading light or the personalair outlet.

Accordingly, those skilled in the art continue with research anddevelopment efforts in the field of aircraft passenger service unitcontrols.

SUMMARY

In one embodiment, the disclosed direction controlled service apparatusmay include a mounting assembly, a housing assembly configured tooperably connect to the mounting assembly, the housing assembly beingmovable with respect to the mounting assembly, and a plurality ofactuators connected between the mounting assembly and the housingassembly, each actuator of the plurality of actuators being configuredto contract upon a current being applied to the actuator.

In another embodiment, the disclosed direction controlled serviceapparatus may include a housing assembly having a ball-shaped housing,the ball-shaped housing including a first ring, a mounting assemblyhaving a socket housing configured to receive the ball-shaped housing,the socket assembly including a second ring; a plurality of actuatorsconnected between the first ring and the second ring, the plurality ofactuators being spaced circumferentially about the first ring and thesecond ring, the ball-shaped housing being configured to rotate withrespect to the socket housing upon contraction of at least one actuatorof the plurality of actuators, and each actuator of the plurality ofactuators being a shape memory alloy wire.

In another embodiment, the disclosed direction controlled serviceapparatus may include a shutter assembly for controlling an air flow ofthe direction controlled service apparatus, the shutter assemblyincluding a collar configured to connect to an opening in a housingassembly of the direction controlled service apparatus, a plurality ofblades disposed within the collar, the plurality of blades beingpositioned adjacent to the opening, each blade of the plurality ofblades being configured to overlap an adjacent blade, a blade actuatoroperably connected to each blade of the plurality of blades, the bladeactuator including a fixed first end and a second end, the bladeactuator being configured to contract upon a current being applied tothe blade actuator, and a toothed rack connected to the second end ofthe blade actuator, the rack being movable upon contraction of the bladeactuator, a locking mechanism movable between an engaged configurationand a disengaged configuration, the locking mechanism being configuredto operably engage the rack upon being set in the engaged configuration,and a locking mechanism actuator operably connected to the lockingmechanism, the locking mechanism actuator being configured to contractupon a current being applied to the locking mechanism actuator to movethe locking mechanism to the disengaged configuration, wherein theplurality of blades at least partially overlap in succession uponcontraction of the blade actuator to at least partially expose theopening, and wherein each blade of the plurality of blades is fixedrelative to the adjacent blade upon engagement of the locking mechanismto the rack.

In another embodiment, the disclosed direction controlled serviceapparatus may include a passenger service unit including a plurality ofdirection controlled service apparatus, each direction controlledservice apparatus including a ball-shaped housing, a socket housingconfigured to receive the ball-shaped housing, a first ring connected tothe ball-shaped housing, a second ring connected to the socket housing,a plurality of actuators connected between the first ring and the secondring, the plurality of actuators being spaced circumferentially aboutthe first and second rings; each actuator of the plurality of actuatorsbeing configured to contract upon a current being applied to theactuator to rotate the ball-shaped housing with respect to the sockethousing, at least one current generating circuit electrically connectedto the plurality of actuators, the current generating circuit beingconfigured to apply electrical current to each actuator of the pluralityof actuators, and a control board electrically connected to the at leastone current generating circuit, the control board being configured toreceive a signal, the signal representing a position of the ball-shapedhousing with respect to the socket housing.

Other aspects of the disclosed direction controlled service apparatuswill become apparent from the following detailed description, theaccompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of an embodiment of the discloseddirection controlled service apparatus;

FIG. 2 is a front view of an example implementation of the discloseddirection controlled service apparatus utilized in an aircraft passengerservice unit;

FIG. 3 is a side sectional view of the disclosed direction controlledservice apparatus;

FIG. 4 is a top plan view of the disclosed direction controlled serviceapparatus;

FIG. 5 is a length versus temperature graph for a typical shape memoryalloy element;

FIG. 6 is a resistance versus temperature graph for a typical shapememory alloy element;

FIG. 7 is a side schematic view of the disclosed direction controlledservice apparatus, depicted in a first position;

FIG. 8 is a side schematic view of the disclosed direction controlledservice apparatus, depicted in a second position;

FIG. 9 is a side schematic view of the disclosed direction controlledservice apparatus, illustrating the actuator and current generatingcircuit;

FIG. 10 is a side schematic view of an implementation of the latchingmechanism of the disclosed direction controlled service apparatus;

FIG. 11 is a side schematic view of another implementation of thelatching mechanism of the disclosed direction controlled serviceapparatus;

FIG. 12 is a side sectional view of an implementation of the discloseddirection controlled service apparatus;

FIG. 13 is a side sectional view of another implementation of thedisclosed direction controlled service apparatus;

FIG. 14 is a schematic view of an implementation of the shutter assemblyof the disclosed direction controlled service apparatus of FIG. 13;

FIG. 15 is a schematic view of another implementation of the shutterassembly of the disclosed direction controlled service apparatus of FIG.13;

FIG. 16 is a schematic view of the aircraft passenger service unit ofFIG. 2; and

FIG. 17 is a schematic illustration showing various functional statesand positions of the disclosed direction controlled service apparatus.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings,which illustrate specific embodiments of the disclosure. Otherembodiments having different structures and operations do not departfrom the scope of the present disclosure. Like reference numerals mayrefer to the same element or component in the different drawings.

Referring to FIG. 1, an embodiment of the disclosed direction controlledservice apparatus, generally designated 10, may include a housingassembly 12 that may be supported for universal movement within amounting assembly 14. The housing assembly 12 may be movable (e.g.,rotated) with respect to the mounting assembly 14 by a plurality ofactuators 16 connected between the housing assembly 12 and the mountingassembly 14.

Referring to FIG. 2, an example implementation of the discloseddirection controlled service apparatus 10 may be utilized as part of apassenger service unit (PSU) 18 of a commercial aircraft cabin. Thefront view illustrates a cabin-side view of the PSU 18, which isavailable to a passenger located inside the aircraft. The PSU 18 mayinclude a service panel 20 and a control board 22 (FIG. 1). The servicepanel 20 may be positioned in front of the control board 22 on the cabinside of the aircraft for designated use and mounting of the PSU 18.

Through the PSU 18, a passenger may be provided with a plurality ofservice functions based on functional electronic units. In the exampleillustrated in FIG. 2, the PSU 18 may include reading lights 24,personal air outlets 26, a plurality of display fields 28 separated fromone another for the representation or display of information (e.g.,fasten seatbelt indicator or restriction of mobile devices), a loudspeaker 30, a plurality of service buttons 32, and the like. Each of thedisplay field 28 may include an assigned light (e.g., light emittingdiode (LED)) to illuminate the display field 28 from behind in order tohighlight the symbol located on the display field 28. The speaker 30 mayinclude an acoustic unit connected to an acoustic module arranged on thecircuit board 22 by a cable or other suitable contact elements (e.g.,contact pins that connect automatically during mounting of the servicepanel 20). The service buttons 32 may include a switching elementarranged on the circuit board and a switch mounted on the service panel20. The service buttons 32 may be mechanically actuated and activated bya passenger (e.g., by pressing the service button 32). The servicebuttons 32 may, for example, notify the cabin crew of an emergency or apassenger need.

It should be noted that the number of components respectively includedon the PSU 18 may differ from the number shown in FIG. 2. For example,more or fewer service buttons 32, reading lights 24, personal airoutlets 26, etc. may be provided.

The control board 22 may include a plurality of functional electronicunits, for example having one or more electronic components, each of theelectronic components being assigned to at least one of the servicefunctions of the PSU 18. In an example implementation, the functionalunits may be connected on a common circuit board permitting acabling-free structure of the PSU 18. For example, connection of thecontrol board 22 to an on-board electrical system of the aircraft may beconfigured using a single cable connection. It is also possible to usecabling-free plug connections, which are connected automatically whenthe PSU 18 is installed. Contactless connections are also contemplated,for example connections based on radio or optical signal transmissionbetween the control board 22, or more precisely the electronic modulesof the functional service units, and the on-board electrical system.

As will be discussed in further detail herein, at least one of thefunctional service units (e.g., the reading light 24 and/or the personalair outlet 26) may include the disclosed direction controlled serviceapparatus 10, which may provide a passenger with the ability to remotelycontrol the position of the service unit and thus the direction of thefunctional output (e.g., light or an air flow).

Referring to FIG. 3, the housing assembly 12 may include a ball-shapedhousing 34 having an interior space 36, a first opening 38 disposed atan upper end of the ball-shaped housing 34 configured to connect theinterior space 36 to a region above the ball-shaped housing 34, and asecond opening 40 disposed at a lower end of the ball-shaped housing 34extending downward from the interior space 36. The ball-shaped housing34 may be formed of any suitably durable and lightweight material, suchas a thermoplastic material, aluminum, an alloy, and the like.

The mounting assembly 14 may include a socket housing 42 having an innercircumferential surface suitably sized and shaped to receive the outercircumferential surface of the ball-shaped housing 34. For example, thesocket housing 42 may include an annular flange having a plurality oflongitudinally extending fingers and a locking ring that encircles theflange across the tips of the fingers to hold the fingers against theouter circumferential surface of the ball-shaped housing 34. As anotherexample, the socket housing 42 may include an annular race mountedwithin the service panel 20 having a partially spherical shape toprovide a front hemispherical engagement with the ball-shaped housing34. Thus, the ball-shaped housing 34 and the socket housing 42 mayprovide for a swivel connection for the housing assembly 12 and themounting assembly 14. Other ball-and-socket connections are alsocontemplated.

Referring back to FIG. 1, the mounting assembly 14 may be connected tothe service panel 20 in a fixed position. For example, the mountingassembly 14 may include a plurality of feet 44 extending radiallyoutward from a base of the socket housing 42 (e.g., the flange or therace). The feet 44 may hold the socket housing 42 in position on theservice panel 20 and may be deflected in a radial direction duringconnection of the direction controlled service apparatus 10 to theservice panel 20. Alternatively, the mounting assembly 14 may include acircumferential ridge and a snap ring to secure the socket housing 42 toa perimeter rim of an aperture in the service panel 20.

Referring again to FIGS. 1 and 3, the housing assembly 12 may include afirst ring 44 extending radially outward from the ball-shaped housing34. The first ring 46 may be disposed about or proximate the upper endof the ball-shaped housing 34. The mounting assembly 14 may include asecond ring 48 extending radially outward from the socket housing 42.The second ring 48 may be disposed about or proximate an upper end ofthe socket housing 34. The first 46 and second 48 rings may each includea solid annular body extending along the respective circumferences ofthe ball-shaped housing 34 and the socket housing 42. Alternatively, thefirst 46 and second 48 rings may each include a plurality of tabs spacedalong the respective circumferences of the ball-shaped housing 34 andthe socket housing 42.

Referring to FIGS. 1 and 4, each of the plurality of actuators 16 may beinterconnected between the first ring 46 and the second ring 48. Each ofthe plurality of actuators 16 may be configured to contract (e.g.,shorten) in response to an applied electrical current to rotate thehousing assembly 12 with respect to the mounting assembly 14. As shownin FIG. 4, the plurality of actuators 16 may be spaced circumferentiallyabout the ball-shaped housing 34 and the socket housing 42. It should benoted that the number of actuators 16 connected between the first ring46 and second ring 48 may differ from the number shown in FIG. 1. Forexample, more or fewer actuators 16 may be provided.

Each actuator 16 may be a wire formed of a shape memory alloy (SMA). Forexample, the SMA may be made from copper-aluminum-nickel ornickel-titanium alloys by alloying zinc, copper, gold and iron. An SMAis an alloy that exhibits a thermoelastic martensite transformation,such that it can be deformed while in the martensite phase and thedeformation is recovered when the SMA returns to the austenite phase. AnSMA is sensitive to temperature or heat. Such heating may beaccomplished through resistive heating (e.g., by passing an electricalcurrent through the SMA part) or through a separate heating element. Forexample, the SMA material may temporarily undergo a dimensional change,such as a change in length at a certain temperature. For example the SMAmaterial may contract (e.g., shorten) at a temperature that is above theambient temperature for the SMA material, and expand at a relativelylower temperature to return to its original condition (e.g., originallength). In this way, the wire actuator 16 made of the SMA material, mayundergo a change in length and a return toward its original length oneor more times via temperature treatment or repeated temperature cycling.

In the process of undergoing a dimensional change, as described above,the SMA material may go through a reversible phase transition ortransformation, or a reversible structural phase transition, upon achange in temperature. The SMAs may have a low temperature phase, ormartensitic phase, and a high temperature phase, or austenitic phase.The particular phase transition associated with a particular SMAmaterial may vary.

The transition from the martensite (low temperature) phase to theaustenite (high temperature) phase in SMAs does not happeninstantaneously at a specific temperature but rather progressesincrementally over a temperature range. FIG. 5 shows the relationshipbetween displacement and temperature, indicating the austenite start(A_(s)) and austenite finish (A_(f)) temperatures, as well as themartensite start (M_(s)) and martensite finish (M_(f)) temperatures. Inthe temperature range indicated by ΔT, the SMA consists of a mixture ofaustenite and martensite. As can be seen, substantially no change inlength occurs below A_(s), and substantially no further change in lengthoccurs above A_(f), as the SMA is heated. Similarly, on coolingsubstantially no change in length occurs above M_(s), and substantiallyno further change in length occurs below M_(f). There is a relationshipbetween the electrical resistance of an SMA part and its temperature, asis shown in FIG. 6, which is shown for an SMA having an Mf above roomtemperature. As can be seen, within the shaded region between R_(min)and R_(max), the resistance can be used as an analog for the SMAtemperature and hence it is possible to deduce the percentagetransformation between the two phases based entirely on the resistancevalue with no direct measurement of temperature.

SMAs suitable for room temperature applications may be those that havean austenite-martensite transition range somewhat above an expectedambient temperature. For example, such as a martensite finishtemperature of about 30-50° C., so that the SMA will remain in itsmartensite phase in the absence of applied heating, and an austenitefinish temperature that is low enough to be compatible with commonengineering plastics, such as an austenite finish temperature of about80-100° C., to minimize the amount of heating (e.g., electrical energyinput to the SMA) required to complete the martensite-to-austenitetransition. SMAs with other transition temperature ranges may be chosenfor actuators 16 designed to operate at decreased (e.g., below 0° C.) orelevated (e.g., above 100° C.) temperature environments.

It should be noted that SMA wire as used in the disclosure may refer toSMA material of elongate form, capable of contraction/elongation along alongitudinal axis. Thus, the term wire does not imply a circularcross-section, although that may be the typical cross-section, butincludes cross-sections that may be elliptical, square, rectangular, orthe like.

It is contemplated that any material that expands by going through aphase transition at a certain temperature and shrinks at a differenttemperature to return toward its original condition may also be used asthe actuators 16.

Referring to FIGS. 7 and 8, the housing assembly 12 may be rotated withrespect to the mounting assembly 14 from a first, non-rotated position(FIG. 7) to a second, rotated position (FIG. 8). In the first position,each actuator 16 a, 16 b, 16 c, 16 d (FIG. 4) of the plurality ofactuators 16 may be in a deformed (e.g., elongated) state interconnectedbetween the first ring 46 and the second ring 48. A first actuator 16 amay contract in response to the applied current and transition to itsoriginal, undeformed, state, thus pulling the first ring 46 toward thesecond ring 48 and rotating the housing assembly 12 with respect to themounting assembly 14 to the second position.

When an SMA part, such as the SMA wire, is deformed within therecoverable range of strain below its martensite finish temperature(M_(f)), and then heated to above the austenite finish temperature(A_(f)), it will revert to its original undeformed shape or length.However, re-cooling of the element below the M_(f) temperature again maynot cause reversion to the deformed shape spontaneously, thus the shapememory effect may be a one-way effect. Therefore, a stress, or bias, mayneed to be applied to the SMA wire for it to revert to the deformedshape as it re-cools below the M_(f) temperature.

Referring still to FIGS. 7 and 8, a bias may be applied to the firstactuator 16 a to cause reversion to the deformed martensitic state asthe SMA wire actuator 16 a cools below the M_(f) temperature. This biasmay be applied by the opposing second actuator 16 b. The opposed secondactuator 16 b may offer greater force availability, since the firstactuator 16 a, when unheated (e.g., when current is removed), mayrequire minimal force to move back to the deformed (e.g., elongated)state.

Referring to FIG. 9, in certain implementations of the discloseddirection controlled service apparatus 10, the actuators 16 may be SMAwire coils. The length of contraction of the actuator 16 is related tothe overall length of the SMA wire. Thus, use of coiled SMA wireactuators 16 may increase the stroke delivered by the actuator 16. Inorder to compensate for any decrease the available force, the thicknessof the wire may be increased.

Each of the plurality of actuators 16 may include a first end 50 and anopposed second end 52. In one implementation, the first end 50 andsecond end 52 of each actuator 16 may be connected to the first ring 46and an intermediate (e.g., middle) location 53 of the actuator 16 may belooped around a wire pulley 54 rotatably connected to the second ring48. For example, the actuator 16 may include a first coiled section 56and a second coiled section 58 separated by an uncoiled section 60. Thefirst coiled section 56 may extend from proximate the first end 50 tothe uncoiled section 60 and the second coiled section 58 may extend fromproximate the second end 52 to the uncoiled section 60. The uncoiledsection 60 may be looped around the pulley 54.

The actuator 16 may be positioned such that its dimensional change willresult in movement of the housing assembly 12 with respect to themounting assembly 14. The SMA actuator 16 may be sufficientlydimensioned such that when the actuator 16 is heated (e.g., a current isapplied) so as to induce phase transition and associated change inlength, the actuator 16 will pull on the first ring 46 and move thehousing assembly 12 with respect to the mounting assembly 14 in one,generally uninterrupted motion.

A current generating circuit 62 may include an electric power source 64and an electrical connection 66 connecting the electric power source 64to both ends 50, 52 of the actuator 16. The current generating circuit62 may be situated along the electrical connection 66 such that pulsesof electricity from the electric power source 64 may be applied to theactuator 16 in response to an actuation signal 184 (FIG. 17). Thecurrent generating circuit 62 may be arranged on the control board 22(FIG. 1) or may be integrated within the housing assembly 12 or mountingassembly 14 and electrically connected to the control board 22.

In another implementation of the disclosed direction controlled serviceapparatus 10, the actuator 16 may be an uncoiled length of SMA wire ormay include a single coiled section extending from proximate the firstend 50 to proximate the second end 52. The first end 50 may be connectedto the first ring 46 and the second end 52 may be connected to thesecond ring 48.

Referring to FIGS. 4, 7, and 8, it can be appreciated that motion of thehousing assembly 12 with respect to mounting assembly 14 may be limitedonly by the number of actuators 16 or by the number of actuators 16 towhich current is applied. For example, if current is applied only to thefirst actuator 16 a (only the first actuator 16 a contracts), thehousing assembly 12 will rotate to the second position (FIG. 8) withrespect to the mounting assembly 14. As another example, if current isapplied only to the third actuator 16 c (only the third actuator 16 ccontracts) the housing assembly 12 will rotate to a third position (notshown) with respect to the mounting assembly 14. As another example, ifcurrent is applied to the first actuator 16 a and the adjacent thirdactuator 16 c (both the first actuator 16 a and the third actuator 16 ccontact), the housing assembly 12 will rotate to a fourth position (notshown) with respect to the mounting assembly 14. The fourth position maybe between the second and third positions.

In an embodiment of the disclosed direction controlled service apparatus10, the socket housing 42 of the mounting assembly 14 may be dimensionedin close tolerance with the ball-shaped housing 34 of the housingassembly 12, such that the housing assembly 12 is secured in any one ofa plurality of fixed positions with respect to the mounting assembly 14by friction. In such an embodiment, the force generated by any one ofthe plurality of actuators 16 may be sufficient to overcome the frictionforce retaining the housing assembly 12 in the fixed position and rotatethe housing assembly 12 with respect to the mounting assembly 14.

Referring to FIGS. 10 and 11, in other embodiments, the discloseddirection controlled service apparatus 10 may include at least onelatching mechanism 68 to secure the housing assembly 12 in a fixedposition with respect to the mounting assembly 14. The latchingmechanism 68 may include a latch 70 and a latch release 72. The latch 70may be movable with respect to the housing assembly 12 between an openconfiguration and a closed configuration. The latch 70 may operablyengage the housing assembly 12 when in the closed configuration tosecure the housing assembly 12 in a fixed position with respect to themounting assembly 14. The latch 70 may be biased in the closedconfiguration by a biasing element, such as a spring, operably connectedto the latch 70 and my urge the latch 70 to the closed configuration. Alatch actuator 74 may be operably connected to the latch 70 andconfigured to move the latch 74 to the open position in response to anapplied current. The latch actuator 74 may be an SMA wire substantiallysimilar to the SMA wire described above for the plurality of actuators16.

The latch release 72 may be movable with respect to the latch 70 betweenan engaged configuration and a disengaged configuration. The latchrelease 72 may be operably engaged with the latch 70 when in the engagedconfiguration to secure the latch 70 in the open configuration withrespect to the housing assembly 12. The latch release may be biased inthe engaged configuration by a biasing element, such as a spring,operably connected to the latch release 72 and may urge the latchrelease 72 to the engaged configuration. A latch release actuator 76 maybe operably connected to latch release 72 and configured to move thelatch release 72 to the disengaged configuration in response to anapplied current. The latch release actuator 76 may be an SMA wiresubstantially similar to the SMA wire described above for the pluralityof actuators 16.

At least one current generating circuit 100 may include an electricpower source 102 and an electrical connection 104 connecting theelectric power source 102 to both ends of the latch actuator 74 and thelatch release actuator 76. The current generating circuit 100 may besituated along the electrical connection 104 such that pulses ofelectricity from the electric power source 102 may be applied to thelatch actuator 74 and the latch release actuator 76 in response to anactuation signal 184 (FIG. 17). The current generating circuit 100 maybe arranged on the control board 22 (FIG. 1) or may be integrated withinthe housing assembly 12 or mounting assembly 14 and electricallyconnected to the control board 22. In one example, a single currentgenerating circuit 100 may be used to transmit the electrical current toboth the latch actuator 74 and the latch release actuator 76. In anotherexample, two current generating circuits 100 may be provided, each ofthe current generating circuits 100 being electrically connected to oneof the latch actuator 74 or the latch release actuator 76. In anotherexample, the latch actuator 74 or the latch release actuator 76 may beelectrically connected to the current generating circuit 62 along withthe plurality of actuators 16 (FIG. 9) as previously described.

As illustrated in FIG. 10, in one example implementation of the latchingmechanism 68 of the disclosed direction controlled service apparatus 10,a plurality of latching mechanisms 68 may be positioned about the firstring 46 of the housing assembly 12. The latch 70 may be a lever member80 pivotably connected to a housing or post adjacent to the ball-shapedhousing 34. As one example, the lever member 80 of the latch 70 may bepivotably connected at a fulcrum by a pin. The lever member 80 of thelatch 70 may engage the ball-shaped housing 34, for example at the firstring 46, when in the closed configuration. The lever member 80 mayinclude a first end having an engagement feature 78 configured tosecurely engage the ball-shaped housing 34. For example, the engagementfeature 78 may be configured to securely engage a peripheral rim of thefirst ring 46, such as a C-shaped clamp. As another example, engagementfeature 78 may be configured to be received by the peripheral rim of thefirst ring 46, such as a pin. Other types of engagement features 78configured to securely engage the housing assembly 12 at other locationsis also contemplated.

The latch release 72 may be another lever member 82 movably connected tothe housing or post adjacent to the ball-shaped housing 34. As oneexample, the lever member 82 of the latch release 72 may be pivotablyconnected at a fulcrum by a pin. As another example, the lever member 82of the latch release 72 may be slidably connected along a track. Thelatch release 72 may engage an opposed second end of the lever member 80of the latch 70 to secure the latch 70 is in the open configuration.

In a normal state, the lever member 80 of the latch 70 may be in theopen configuration and the lever member 82 of the latch release 72 maybe in the engaged configuration securing the latch 70 in the openconfiguration. When the housing assembly 12 is rotated to a rotatedposition with respect to the mounting assembly 14 (e.g., by one or moreof the actuators 16), a current may be applied to the latch releaseactuator 76 to contract the latch release actuator 76 (transition thelatch release actuator 76 back to its non-deformed state) and move thelever member 82 of the latch release 72 to the disengaged configurationreleasing the lever member 80 of the latch 70. The biasing element mayurge the lever member 80 of the latch 70 to the closed configuration,such that the engagement feature 78 securely engages the ball-shapedhousing 34 in the fixed rotated position with respect to the sockethousing 42. Upon a current being applied to the latch actuator 74, thelatch actuator 74 may contract (transition the latch actuator 74 back toits non-deformed state) and move the lever member 80 of the latch 70 tothe open configuration. The biasing element of the latch release 72 mayurge the lever member 82 of the latch release 72 back to the engagedconfiguration to retain the lever member 80 of the latch 70 in the openconfiguration.

It can be appreciated that the secured position of the housing assembly12 with respect to the mounting assembly 14 may be limited only by thenumber of latching mechanisms 68. For example, four latching mechanisms68 may secure the housing assembly 12 in four distinct fixed positionsrelative to the mounting assembly 14. Additional latching mechanisms 68may provide for additional secured positions.

As illustrated in FIG. 11, in another example implementation of thelatching mechanism 68 of the disclosed direction controlled serviceapparatus 10, a plurality of latching mechanisms 68 may be positionedabout the ball-shaped housing 34 of the housing assembly 12 and thesocket housing 42 of the mounting assembly 14. The latch 72 may be aplunger member 84 slidably connected within a housing positionedadjacently to the ball-shaped housing 34. As one example, the plungermember 84 of the latch 72 may be spring loaded and movable within atubular housing. The plunger member 84 of the latch 70 may engage theball-shaped housing 34 when in the closed configuration. The plungermember 84 may include a first end having an engagement feature 86configured to securely engage the ball-shaped housing 34. For example,the engagement feature 86 may be a detent configured to be securelyreceived within a recess 88 of the ball-shaped housing 34. Theball-shaped housing 34 may include a plurality of recesses 88 positionedupon the outer circumferential surface. The position of each of therecesses 88 may correspond to a fixed rotated position of the housingmember 12 with respect to the mounting member 14.

For example, the plunger member 84 may be positioned outside of thesocket housing 42 and the socket housing 42 may include a plurality ofthrough-hole apertures 90 configured to allow the engagement feature 86(e.g., the detent) to pass through the socket housing 42 and engage analigned recess 88 in the ball-shaped housing 34. As another example, theplunger member 84 may be positioned outside of the ball-shaped housing34 and engage a proximate recess 88 in the ball-shaped housing 34. Othertypes of engagement features 86 configured to securely engage thehousing assembly 12 at other locations is also contemplated.

The latch release 72 may be a pin 92 movably connected to the tubularhousing adjacent to the engagement feature 86. As one example, the pin92 of the latch release 72 may be spring loaded and movable within atubular housing. The pin 92 of the latch release 72 may engage an end ofthe engagement feature 86 of the latch 70 to secure the latch 70 is inthe open configuration.

In a normal state, the plunger member 84 of the latch 70 may be in theopen configuration and the pin 92 of the latch release 72 may be in theengaged configuration securing the latch 70 in the open configuration.When the housing assembly 12 is rotated to a rotated position withrespect to the mounting assembly 14 (e.g., by one or more of theactuators 16), a current may be applied to the latch release actuator 76to contract the latch release actuator 76 (transition the latch releaseactuator 76 back to its non-deformed state) and move the pin 92 of thelatch release 72 to the disengaged configuration releasing the plungermember 84 of the latch 70. The biasing element may urge the plungermember 84 of the latch 70 to the closed configuration, such that theengagement feature 78 is receivably engaged within the recess 88 of theball-shaped housing 34 aligned with the aperture 90 of the sockethousing 42 to secure the ball-shaped housing 34 in the fixed rotatedposition with respect to the socket housing 42. Upon a current beingapplied to the latch actuator 74, the latch actuator 74 may contract(transition the latch actuator 74 back to its non-deformed state) andmove the plunger member 84 of the latch 70 to the open configuration.The biasing element of the latch release 72 may urge the pin 92 of theback to the engaged configuration to retain the plunger member 84 of thelatch 70 in the open configuration.

Alternatively, the latching mechanism 68 may not include the latchrelease 72. In such an embodiment, the plunger member 84 may be retainedin the open configuration by contact with the outer circumferentialsurface of the ball-shaped housing 34.

The SMA wire of the latch actuator 74 and the latch release actuator 76may be configured to provide sufficient force to overcome the biasingforce provided by the biasing elements of the latch 70 and latch release72, respectively, upon application of current. The biasing forceprovided by the biasing elements of the latch 70 and the latch release72 may be configured to return the latch actuator 74 and the latchrelease actuator 76, respectively, to their deformed (e.g., extended)state.

It can be appreciated that the secured position of the housing assembly12 with respect to the mounting assembly 14 may be limited only by thenumber of latching mechanisms 68 and the number of recesses 88 disposedin the ball-shaped housing 34. For example, four latching mechanisms 68and four recesses 88 may secure the housing assembly 12 in four distinctfixed positions relative to the mounting assembly 14. Additionallatching mechanisms 68 and recesses 88 may provide for additionalsecured positions.

Referring to FIG. 12, in an implementation, the disclosed directioncontrolled service apparatus 10 may be configured for use as a readinglight 24 (FIG. 2). The housing assembly 12 may include a light-emittingdiode (LED) module 94 housed within the lower end of the ball-shapedhousing 34. The LED module 94 may include a generally circular shapesuitably sized to fit within the second opening 40 of the ball-shapedhousing 34. An electrical circuit may be formed by connecting the LEDmodule 94 and the power source. For example, the LED module 94 mayinclude an electrical connection extending through the interior space 36of the ball-shaped housing 34 for connection to the electric powersource. Alternatively, the LED module 94 may include a plurality ofelectrical connections or terminals for operable contact with aplurality of complimentary electrical connections or terminals disposedaround the peripheral rim of the second opening 40.

The LED module 94 may include, or house, a plurality of light-emittingdiodes (LEDs) 108. The LEDs 108 may be arranged in any pattern upon theLED module 94. The LED module 94 may be connected to the control board22, which may include a switch module for illuminating the LEDs 108 upontransmission of an activation signal 182 (FIG. 17). Optionally, thehousing assembly 12 may include a reflector (not shown) disposed behindthe plurality of LEDs 108. A lens 110 may be connected over the secondopening 40. For example, the lower end of the ball-shaped housing 34 mayinclude a downwardly extending annular lip 112. The lip 112 may includethreading on an exterior surface. A collar 114 may house the lens 110and include a continuous sidewall. The sidewall may include threadingdisposed on an interior surface for connection to the lip 112.

Referring to FIG. 13, in another implementation, the disclosed directioncontrolled service apparatus 10 may be configured for use as a personalair unit 26 (FIG. 2), such as a gasper. The housing assembly 12 mayinclude a conduit connector 116 extending from the ball-shaped housing34 configured to connect to an air source (e.g., a duct in the lowpressure low volume air system contained within the PSU 18 (FIG. 2) orthe cabin ceiling of the aircraft). For example, the connector 116 maybe a flexible conduit connector to allow for rotating motion of thehousing assembly 12. An air flow (denoted by arrow) may be provided fromthe air source (not shown) through the interior space 36 of theball-shaped housing 34 from the first opening 38 to the second opening40.

The housing assembly 12 may also include a shutter assembly 118connected to the lower end of the ball-shaped housing 34 about thesecond opening 40 to adjust the air flow from personal air unit 26between no air output and a fairly substantial air output. For example,the lower end of the ball-shaped housing 34 may include a downwardlyextending annular lip 120. The lip 120 may include threading on anexterior surface. The shutter assembly 118 may include a collar 122having a continuous sidewall. The sidewall may include threadingdisposed on an interior surface for connection to the lip 120.

Referring to FIG. 14, in one implementation, the shutter assembly 118may include a plurality of blades 124. The plurality of blades 124 maybe positioned adjacent to (e.g., below) the second opening 40, forexample, by connecting the shutter assembly 118 to the lower end of theball-shaped housing 34 about the second opening 40. While only three (3)blades 124 are shown by illustration, it can be appreciated that anynumber of blades 124 may be used. Each of the blades 124 may bepivotably connected to one another, such that each blade 124 may besuccessively rotated upon an adjacent blade 124 in order to expose alarger portion of the second opening 40 of the ball-shaped housing 34(FIG. 13), thus providing for a greater air flow.

A blade actuator 126 may be connected to each of the blades 124 and atleast partially circumscribe the second opening 40. For example, theblade actuator 126 may extend along a path provided by the collar 122,such as an integral groove or through-hole. The blade actuator 126 maybe configured to contract in response to an applied electrical currentand rotate the blades 124 with respect to one another. The bladeactuator 126 may be an SMA wire substantially similar to the SMAactuators described herein.

The blade actuator 126 may have a first end 128 at a fixed location, forexample fixed to the collar 122 (FIG. 13). A second end 130 of the bladeactuator 126 may be connected to a toothed rack 132. The rack 132 may bemovable in opposing directions. For example, the rack 132 may be movablealong a track (not shown) on the collar 122. Upon application ofcurrent, the blade actuator 126 may contract (e.g., shorten), thusdrawing the blades 124 in upon themselves and moving the rack 132. Itcan be appreciated that the change in length of the blade actuator 126may be determined by the energy (e.g., electrical current) applied, asdiscussed above (FIGS. 5 and 6).

A locking mechanism 134 may be positioned adjacent to the rack 132. Thelocking mechanism 134 may include a lever member 136 pivotably connectedto a support, such as the collar 122. The lever member 136 of thelocking mechanism 134 may be movable with respect to the rack 132between an engaged configuration and a disengaged configuration. A firstend 140 of the lever member 136 may include an engagement feature 138configured to operably engage the rack 132 and secure the rack 132 in afixed position, when the lever member 136 is in the engagedconfiguration. For example, the engagement feature 138 may be a detentconfigured to be received within a gap formed between adjacent teeth ofthe rack 132.

The teeth of the rack 132 may be configured such that the lever member136 of the locking mechanism 134 may restrict movement of the rack 132in opposing directions when in the engaged configuration. For example,the rack 132 may include two sets of opposing teeth, such that theengagement feature 138 of the lever member 136 may engage a tooth of thefirst set of teeth to restrict movement in one direction and engage atooth of the opposing second set of teeth to restrict movement in theopposite direction.

The rack 132 may be biased to a position corresponding to a fully closedposition of the plurality of blades 124 by a biasing element. Thebiasing element may be a spring or an apposing SMA actuator configuredto contract in response to an applied current.

The locking mechanism 134 may be biased in the engaged configuration bya biasing element, such as a spring, operably connected to the levermember 136 and may urge the lever member 136 to the engagedconfiguration. A locking mechanism actuator 144 may be operablyconnected to a second end 142 of the lever member 136 and configured tomove the locking mechanism 134 to the disengaged position in response toan applied current. The locking member actuator 144 may be an SMA wiresubstantially similar to the SMA wire described above.

Upon actuation (e.g., contraction) of the locking mechanism actuator144, the lever member 136 may move to the disengaged position, thusallowing the biasing element to return the rack 132 toward the positioncorresponding to a fully closed position of the plurality of blades 124and returning the blade actuator 126 to its deformed (e.g., elongated)state.

The locking mechanism actuator 144 may be configured to hold the levermember 136 in the disengaged position only long enough for the rack 132to move toward the position corresponding to a fully closed position ofthe plurality of blades 124 (e.g., via the biasing element) or away fromthe position corresponding to a fully closed position of the pluralityof blades 124 (e.g., via the blade actuator 126) incrementally. Thebiasing element of the locking mechanism 134 may return the lever member136 to the engaged configuration and return the locking mechanismactuator 144 to its deformed (e.g., elongated) state. In such a manner,the relative position of the blades 124 may be incrementally adjusted toadjust the air flow through the second opening 40.

At least one current generating circuit 146 may include an electricpower source 148 and an electrical connection 150 connecting theelectric power source 148 to both ends of the blade actuator 126 and thelocking mechanism actuator 144. The current generating circuit 146 maybe situated along the electrical connection 150 such that pulses ofelectricity from the electric power source 148 may be applied to theblade actuator 126 and the locking mechanism actuator 144 in response toan air flow control signal 186 (FIG. 17). The current generating circuit146 may be arranged on the control board 22 or may be integrated withinthe housing assembly 12 or mounting assembly 14 and electricallyconnected to the control board 22. In one example, a single currentgenerating circuit 146 may be used to transmit the electrical current toboth the blade actuator 126 and the locking mechanism actuator 144. Inanother example, two current generating circuits 146 may be provided,each of the current generating circuits 146 being electrically connectedto one of the blade actuator 126 or the locking mechanism actuator 144.In another example, the blade actuator 126 and the locking mechanismactuator 144 may be electrically connected to the current generatingcircuit 62 along with the plurality of actuators 16 (FIG. 9) aspreviously described.

Referring to FIG. 15, in another implementation, the shutter assembly118 may include a rigid frame 154 and a flexible diaphragm 162. Theframe 154 and diaphragm 162 may be positioned adjacent to (e.g., below)the second opening 40 of the ball-shaped housing 34, for example, byconnecting the shutter assembly 118 to the lower end of the ball-shapedhousing 34 about the second opening 40.

The frame 154 may include a central hub 156, an outer perimeter framemember 158, and plurality of radial frame members 160 extending radiallyfrom the hub 156 to the perimeter frame member 158. The perimeter framemember 156 may be connected to the interior of the collar 122 (FIG. 13).The diaphragm 162 may include a central region 163 (e.g., a middle area)and a perimeter 165. The central region 163 of the diaphragm 162 may beconnected to the central hub 156 of the frame 154. The diaphragm 162 maybe a thin sheet of flexible material (e.g., rubber) forming a partitionor barrier to the air flow exiting through the second opening 40 of theball-shaped housing 34. The diaphragm 162 may be configured tocompletely cover the second opening 40 when in a fully expanded positionand at least partially expose the second opening 40 when in a partiallyor fully contracted position. The perimeter 165 of the diaphragm 162 maybe located proximate the perimeter frame member 158 of the frame 154when the diaphragm 162 is in the fully expanded position.

A plurality of diaphragm actuators 164 may be connected between the hub156 and a perimeter of the diaphragm 162. The plurality of diaphragmactuators 164 may be spaced along the perimeter 165 of the diaphragm162. The diaphragm actuators 164 may be configured to contract inresponse to an applied electrical current and pull the perimeter 165 ofthe diaphragm 162 toward the hub 154 placing the diaphragm 162 in atleast a partially contracted position. The diaphragm actuators 164 maybe an SMA wire substantially similar to the SMA actuators describedherein.

For example, each of the diaphragm actuators 164 may include a first end166 and an opposed second end 168. Both ends 166, 168 of the diaphragmactuator 164 may be connected to the hub 156 and an intermediate (e.g.,middle) location of the diaphragm actuator 164 may be looped through orotherwise connected to the perimeter 165 of the diaphragm 162. Thediaphragm 162 may be biased in the fully expanded position to entirelycover the second opening 40. Upon application of current, the diaphragmactuators 164 may contract (e.g., shorten), thus drawing the perimeter165 of the diaphragm 162 inward toward the hub 156. Thus, the positionof the perimeter 165 of the diaphragm 162 with respect to the perimeterframe member 158 may be adjustable to control the air flow exiting fromthe second opening 40. It can be appreciated that the change in lengthof the diaphragm actuators 164 may be determined by the energy (e.g.,electrical current) applied, as discussed above (FIGS. 5 and 6), andthus contracted position of the diaphragm 162 (e.g., position of theperimeter 165 of the diaphragm 162 with respect to the perimeter frame158 of the frame 154.

A diaphragm retaining mechanism may be provided to retain the perimeterof the diaphragm 162 in a contracted position with respect to theperimeter frame member 158. The diaphragm retaining mechanism mayinclude a latch having a latch actuator and a latch release having alatch release actuator similar to those described herein.

At least one current generating circuit 170 may include an electricpower source 172 and an electrical connection 174 connecting theelectric power source 172 to both ends 166, 168 of each of the pluralityof diaphragm actuators 164. The current generating circuit 170 may besituated along the electrical connection 174 such that pulses ofelectricity from the electric power source 172 may be applied to all ofthe diaphragm actuators 164 in response to an air flow control signal186 (FIG. 17). The current generating circuit 170 may be arranged on thecontrol board 22 or may be integrated within the housing assembly 12 ormounting assembly 14 and electrically connected to the control board 22.Alternatively, the diaphragm actuators 164 may be electrically connectedto the current generating circuit 62 along with the plurality ofactuators 16 (FIG. 9) as previously described.

In another implementation, the disclosed direction controlled serviceapparatus 10 may be configured for use as both a reading light 24 and apersonal air outlet 26 (FIG. 2). For example, the LED module 94 (FIG.12) may include a ring shape having a plurality of LEDs 108. Thering-shaped LED module may be connected to the lower end of theball-shaped housing 34 outside of and around the perimeter of the secondopening 40. The shutter assembly 118 (FIG. 13) may be connected to thelower end of the ball-shaped housing 34 over the second opening 40(e.g., within the ring-shaped LED module).

Referring to FIG. 16, the passenger service unit 18 may be positioned inthe cabin of an aircraft and with respect to a seat group. FIG. 16represents a plurality of direction controlled service apparatus 10utilized with and connected to the service panel 20. It can beappreciated that the direction controlled service apparatus 10 shown canbe either a reading light 24 (FIG. 12) or a personal air outlet 26 (FIG.13).

The direction controlled service apparatus 10 may be arranged directlyabove a corresponding passenger seat 178. Each seat 178 may include acontrol unit 180. The control unit 180 may be configured to communicatewith the direction controlled service apparatus 10 corresponding to theseat 178. For example, the control unit 180 may communicate with thecontrol board 22 of the PSU 18 to control the function and position ofthe corresponding direction controlled service apparatus 10. Forexample, the control unit 180 may transmit a signal to control theposition and function of the direction controlled service apparatus 10corresponding to the seat 178.

FIG. 17 shows various different positions and functions of the directioncontrolled service apparatus 10. Under heading “A” of FIG. 17, thedirection controlled service apparatus 10 may initially be OFF (e.g., noillumination or air flow being distributed from the apparatus 10) andpositioned in a first position (FIG. 7). Under heading “B” of FIG. 17,the direction controlled service apparatus 10 may be utilized as areading light 24 (FIG. 12). In response to an activation signal 182transmitted by the control unit 180, the LED module 94 (FIG. 12) may beenergized and transmit illumination (denoted by the arrow) directedtoward the corresponding seat 178. Under heading “C” of FIG. 17, inresponse to an actuation signal 184 transmitted by the control unit 180,the housing assembly 12 (FIG. 1) may rotate to a second position (FIG.8) with respect to the mounting assembly 14 and also with respect to thecorresponding seat 178. Under heading “D” of FIG. 17, in response toanother actuation signal 184 transmitted by the control unit 180, thehousing assembly 12 may rotate to a third position with respect to themounting assembly 14 and also with respect to the corresponding seat178.

Under heading “E” of FIG. 17, the direction controlled service apparatus10 may be utilized as a personal air outlet 26 (FIG. 13). In response toan air flow control signal 186 transmitted by the control unit 180, theshutter assembly 118 (FIG. 13) may open allowing an air flow (denoted bythe plurality of arrows) directed toward the corresponding seat 178.Under heading “F” of FIG. 17, in response to another air flow controlsignal 186 from the control unit 180 the amount of air flow from thepersonal air outlet 26 may be restricted by partially closing theshutter assembly 118. In response to an actuation signal 184 transmittedby the control unit 180, the housing assembly 12 may rotate to a secondposition with respect to the mounting assembly 14 and also with respectto the corresponding seat 178.

The various signals transmitted to the control board 22 from the controlunit 180 may be wired or wireless signals. In a wired embodiment,electrical connections may be routed from the control unit 180 of eachseat 178 through the body of the cabin and to the control board 22 ofthe PSU 18. In a wireless embodiment, the control unit 180 may include awireless transmitter configured to transmit a wireless signal (e.g.,radio frequency). The control board 22 may include a wireless receiverconfigured to receive the wireless signal transmitted by the controlunit 180. The control board 22 may also include a processing moduleconfigured to process the wireless signal and provide a control signalto the direction controlled service apparatus 10, for example,controlling the position of the housing assembly 12 with respect to themounting assembly 14, energizing/de-energizing the LED module 94, oropening/closing the shutter assembly 118.

Accordingly, the disclosed direction controlled service apparatus mayprovide a seat level control for passengers of an aircraft that providesservice function control of the passenger service unit corresponding totheir seat.

Although various aspects of the disclosed direction controlled serviceapparatus have been shown and described, modifications may occur tothose skilled in the art upon reading the specification. The presentapplication includes such modifications and is limited only by the scopeof the claims.

What is claimed is:
 1. A passenger service unit comprising: a pluralityof direction controlled service apparatus, each direction controlledservice apparatus comprising: a ball-shaped housing, a socket housingconfigured to receive said ball-shaped housing; a first ring connectedto said ball-shaped housing; a second ring connected to said sockethousing; and a plurality of actuators connected between said first ringand said second ring, said plurality of actuators being spacedcircumferentially about said first and second rings, each actuator ofsaid plurality of actuators being configured to contract upon a currentbeing applied to said actuator to rotate said ball-shaped housing withrespect to said socket housing.
 2. The passenger service unit of claim 1wherein each direction controlled service apparatus further comprises atleast one current generating circuit electrically connected to saidplurality of actuators, said current generating circuit being configuredto apply electrical current to each actuator of said plurality ofactuators.
 3. The passenger service unit of claim 2 wherein eachdirection controlled service apparatus further comprises a control boardelectrically connected to said at least one current generating circuit,said control board being configured to receive a signal, said signalrepresenting a position of said ball-shaped housing with respect to saidsocket housing.
 4. The passenger service unit of claim 3 wherein saidsignal is a wireless signal.
 5. The passenger service unit of claim 1wherein each actuator of said plurality of actuators comprises a shapememory alloy wire.
 6. The passenger service unit of claim 5 wherein saidshape memory alloy wire comprises nickel.
 7. The passenger service unitof claim 5 wherein said shape memory alloy wire comprises acopper-aluminum-nickel alloy.
 8. The passenger service unit of claim 5wherein said shape memory alloy wire comprises a nickel-titanium alloy.9. The passenger service unit of claim 5 wherein said shape memory alloywire has a martensite finish temperature between about 30° C. and about50° C.
 10. The passenger service unit of claim 9 wherein said shapememory alloy wire has an austenite finish temperature between about 80°C. and about 100° C.
 11. The passenger service unit of claim 1 whereinsaid plurality of actuators are equidistantly spaced about said firstand second rings.
 12. The passenger service unit of claim 1 furthercomprising at least one locking mechanism configured to releasablysecure said ball-shaped housing in a fixed position with respect to saidsocket housing.
 13. The passenger service unit of claim 12 wherein saidlocking mechanism comprises a latch movable between an open and a closedconfiguration, said latch being configured to operably engage saidball-shaped housing upon being set in said closed configuration.
 14. Thepassenger service unit of claim 13 wherein said locking mechanismfurther comprises a latch release movable between an engaged and adisengaged configuration, said latch release being configured tooperably engage said latch upon being set in said engaged configuration.15. The passenger service unit of claim 14 wherein said lockingmechanism further comprises a latch actuator operably connected to saidlatch, said latch actuator being configured to move said latch into saidopen configuration.
 16. The passenger service unit of claim 15 whereinsaid locking mechanism further comprises a latch release actuatoroperably connected to said latch release, said latch release actuatorbeing configured to move said latch release into said disengagedconfiguration.
 17. The passenger service unit of claim 16 wherein saidlatch actuator and said latch release actuator are each configured tocontract upon a current being applied to one of said latch actuator orsaid latch release actuator.
 18. The passenger service unit of claim 17wherein said latch actuator and said latch release actuator eachcomprise a shape memory alloy wire.
 19. The passenger service unit ofclaim 18 wherein said shape memory alloy wire comprises nickel.
 20. Thepassenger service unit of claim 18 wherein said shape memory alloy wirehas a martensite finish temperature between about 30° C. and about 50°C. and an austenite finish temperature between about 80° C. and about100° C.